High mobility group box-1 expression correlates with poor outcome in lung injury patients

Chest trauma is frequently followed by pulmonary contusion and sepsis. High mobility group box-1 (HMGB-1) is a late mediator of severe sepsis that has been associated with mortality under experimental conditions. We studied HMGB-1 mRNA expression in patients with lung injury and its relationship with the severity of trauma and survival. A total of 24 consecutive patients with chest trauma referring to the Intensive Care Unit of Messina University Hospital, were enrolled. Lung trauma was established on the basis of chest X-ray and computed tomography. Injury Severity Score (ISS), Revised Trauma Score (RTS) and Glasgow Coma Scale (GCS) were also assessed. Accordingly to these results 6 patients were considered as controls because of no penetrating trauma and low ISS. Blood and broncho-alveolar lavage fluid (BALF) from chest trauma patients were withdrawn at admission and 24h after the beginning of the standard therapeutic protocol. HMGB-1 mRNA increased significantly in blood (r=0.84) and BALF (r=0.87) from patients with trauma and pulmonary contusion and positively correlated with the severity of trauma (based on ISS and RTS) and the final outcome. HMGB-1 protein levels were also elevated in BALF macrophages from severe trauma patients compared to control subjects, furthermore TNF-alpha and its receptor TNFR-1 mRNA levels were also markedly increased in patients with a poor outcome respect to other subjects. Our study suggests that HMGB-1 may be an early indicator of poor clinical outcome in patients with chest trauma.